How do anti-lag systems work

[tangoed sparky]

I have always wondered how the anti-lag systems used in rallying and some race cars work. I think that it is somthing to do with retarding the ignition until the exaust valves are starting to open but it must be more complicated then that. Or is it?

[AlexF]

Your thinking along the right lines, but it is a bit more complicated than that!!!

have a look at

http://www.wrc-cosworth.org/tech/tuning/antilag.html


alex

[tangoed sparky]

nice one thanks Alex

[KC]

There was a system employed in WRC where a small electric motor spooled up the turbocharger to give instant throttle repsonse.

[avsfan733]

http://tentenths.com/forum/showthrea...threadid=35160

[tangoed sparky]

thank avsfan733

[chunder]

Apparently in the Group B days, the cars were developing so much power the engineers from the factory teams realised that anti-lag was necessary. I know Peugeot used a very basic version and Audi used something that made the car bang really loud. Lancai obviously used a blower to try and get over it.
Would be interesting to see how the engineers deveoped it in Group S.
I know for a fact taht the first time I heard it on the RAC in must of been 91 I thought the cars were breking down, they sounded so weird.

[avsfan733]

would something like CO2 injected at a tangent the turbine be legal under the current WRC rules? only problem i can for see would be the instantaneous supercoolin effect, maybe add a third wheel specifically for acceleration by some sort of compressed gas? its additional weight but its also a little more inertia that stays spinning.

I have long wondered about use of the throttle bodies to control turbo lag. could you put the throttle body before the turbo, and then simply but a bypass valve in reverse after it to provide the required minimal air? (much like that used by AEM to save engines from ingesting water) That way the compressed air doesn't back up and the turbo isn't working to compress air, its simply freewheeling and taking any acceleratioin that the bypassed air gives it as exhaust pulses.